The present invention relates to towing vehicles, and more particularly to an attachable boom accessory for flatbed a tow truck.
Towing vehicles, commonly known as "tow trucks", include traditional types having rear-mounted hoist booms in addition to more recently developed flatbed trucks that employ tilting and extension mechanisms for orienting a bed member as an inclined ramp for receiving a vehicle, the bed being moved to a horizontally oriented carrying position subsequent to receipt of the vehicle. The truck is equipped with a cable winch that is located at or ahead of a front extremity of the bed for drawing the vehicle onto the bed. When the winch is required to move a vehicle from a relatively remote location (such as when retrieving a vehicle that has left the road), the bed and/or the cable is subject to becoming damaged as the cable is drawn forcibly over a rear extremity of the bed. Attempts to overcome this difficulty include sheave and/or boom attachments for connection to anchor points that are normally provided on rear portions of the bed.
It is also known to provide hydraulic underlifts at the rear of flatbed tow trucks, the underlifts having a wheel lift or "T-bar" connected thereto for towing a vehicle in addition to the load carried on the bed.
The sheave and/or boom attachments of the prior art are subject to a number of disadvantages, including the following:
1. The bed provides insufficient structural integrity for supporting the attachment, particularly against oblique loading as can occur when the vehicle or other load to be acquired is some distance to one side or below the tow truck; PA1 2. They are awkward and time-consuming to install and remove from the truck; and PA1 3. The excessively interfere with normal load-carrying on the bed. PA1 (a) providing a boom accessory having a base and a boom member extending upwardly and rearwardly from the base, a sheave being rotatably mounted from the boom member; PA1 (b) extending the ram; PA1 (c) resting the base on the ram; PA1 (d) retracting the ram for clamping the base between the head portion of the ram and the leg member; PA1 (e) threading the cable over the sheave; PA1 (f) connecting the cable to the load; and PA1 (g) activating the winch for moving and hoisting the load, the cable being movably supported by the sheave.
Thus there are many instances in which a flatbed tow truck is used for responding to an emergency, and upon arrival at the scene it is discovered that a boom-type tow truck is needed for retrieving a disabled vehicle that is stuck in sand or the like. Unless special retrieval difficulties are known to exist, the dispatch of boom-type tow trucks is normally avoided, especially in multi-vehicle emergencies, because such trucks can tow only a single vehicle. In contrast, a flatbed truck having an auxiliary lift can tow a pair of disabled vehicles.
Accordingly, there is a need for a hoist boom accessory for flatbed tow trucks that avoids the disadvantages of the prior art.